ICITRU : Randomized Trial of Immunonutrition With L-citrulline in Patients Hospitalized in Intensive Care for Sepsis or Septic Shock

Inclusion Criteria: * Septic patients in accordance with the definition of sepsis and septic shock published in 2016 (JAMA) and whose use is recommended by the European Society of Intensive Care Medicine; * Initial aggression dated less than 4 days before admission to intensive care (selection of "community" patients). The onset of aggression will be defined by the onset of clinical signs of infection; * Patients hospitalized for less than 48 hours before admission to intensive care (selection of patients without malnutrition and immunosuppression acquired in hospital) \*; * Patients under invasive mechanical ventilation with a foreseeable ventilation duration\> 2 days \*\*; * Exclusive enteral nutrition; * Affiliation to a social security scheme; * Consent signed by the patient, relative or legal representative or inclusion under emergency procedure Non Inclusion Criteria: * Progressive Sars-CoV2 infection * Pregnancy in progress; * Morbid obesity (BMI\> 40); * State of immunosuppression defined by at least one of these criteria: continuous administration of steroids at any dose for more than one month before hospitalization, steroids at high doses (\> 0.5 mg / kg / day of methylprednisolone or equivalent), radiotherapy or chemotherapy in the previous year, proven humoral or cellular deficiency; * Contraindication to enteral nutrition (SRLF 2016 recommendations: "Enteral nutrition should probably not be used upstream of a high flow digestive fistula in cases of intestinal obstruction, ischemia of the small intestine or digestive hemorrhage. active (Strong agreement) "); * Participation in intervention research on a drug, or intervention research that could impact the immune system Exclusion Criteria: \- Institution of immunosuppressive therapy such as chemotherapy, cyclophosphamide, high dose corticosteroid therapy (\> 0.5 mg / kg / day ; hydrocortisone used in the management of septic shock is not considered an exclusion criterion).